Lamp lead wire terminal



' J 1969 w. E. CARPENTER ETAL 3,422,302

LAMP LEAD WIRE TERMINAL Filed April 11, 1967 United States Patent O 3,422,302 LAMP LEAD WIRE TERMINAL Walter E. Carpenter, Cedar Grove, and Lawrence Varick,

Haledon, NJ., assignors to Wagner Electric Corporation, a corporation of Delaware Filed Apr. 11, 1967, Ser. No. 630,080 U.S. Cl. 313318 Int. Cl. H01j /48; 5/50 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a terminal for an electric lamp or other electrical device enclosed in a glass envelope. Most electric lamps are fitted with a base made of some type of plastic, such as bakelite, or metal shell and including conducting pins or contacts. The conducting pins or contacts must be soldered to the lead-in wires to form a complete circuit for the lamp components within the envelope. Such bases are expensive and require time and material to join to the lead wires. Some of the newer types of lamps, especially the wery small types have been made and used without the bases. These lamps have had the disadvantage of failure because of broken lead-in wires and because the molten glass did not flow around the lead-in terminals to form a strong symmetrical base.

The present invention comprises a single wire terminal which may be a continuation of a conductive sealing wire connected to an electrode inside the envelope. An end portion of the sealing wire is bent at an angle of approximately 45 to the lamp axis, and a first imbedded portion of the wire terminal continues in the same direction. Then, a contact portion of the wire terminal is bent so as to be at right angles to the axis, and finally a second imbedded portion of the wire terminal is bent at an angle substantially equal to that of the first imbedded portion to form a second brace for the wire terminal. It is important that a space be left between the end of the second imbedded portion and the first imbedded portion.

Further details of the invention will be readily understood by reference to the accompanying drawings which illustrate one embodiment of the invention and of which:

FIG. 1 is a cross-sectional view of the terminal wire and the unsealed glass tube. This view is taken along line 11 of FIG. 2.

FIG. 2 is an end view of the terminal wire and unsealed glass tube shown in FIG. 1.

FIG. 3 is a side view of the finished seal and terminal after the molten glass has been pressed into place.

FIG. 4 is an end view of the terminal and seal shown in FIG. 3.

Referring now to the drawings, FIGS. 1 and 2 show a 3,422,302 Patented Jan. 14, 1969 "ice glass tube 10 which is part of an envelope containing lamp components. A lamp sealing wire 11 is positioned in axial alignment with the tube 10 and may be temporarily secured in this position by a jig (not shown). The end of the seal wire 11 is welded (blackened area) to a terminal wire 12 and the terminal wire is bent to form a first imbedded portion 13 and a contact portion 14. A second imbedded portion 15 is bent for anchoring the wire end. The imbedded portions 13 and 15 may make an angle of 30 degrees with the tube axis. The contact portion 14 is generally straight and is disposed at right angles to the tube axis although this portion of the lead wire may take other shapes depending upon the design of the socket into which the terminal is to be used. It is important to provide a space between the end of portion 15 and the main sealing wire 11 and terminal wire portion 13. This space permits the molten glass to flow in and around all surfaces of the sealing portions 13 and 15 without the formation of voids or bubbles.

In order to seal the wires 11 and 12 into the end of the tube 10, the glass is softened in the usual manner and then the sides of the tube are pressed together by a clamping means. After the seal has been made, the lamp includes a pressed end portion 16 as shown in FIGS. 3 and 4. Contact portion 14 extends above the end portion 16 while the end of the second imbedded portion 15 is entirely enclosed by glass.

One of the reasons for forming the imbedded portions 13 and 15 as shown, is to produce a symmetrical pressed end 16'. The surface of the end portion 16 includes no uncontrolled irregularities and for this reason the seal is considerably stronger than other nonsymmetrical press shapes. Also, the end portion 1-6 is easier to anneal and when finished has fewer internal strains. A further advantage is that the weld between wires 11 and 12 is imbedded in the end portion 16 and thereby reinforced against breakage.

It will be understood that it is intended to cover all changes and modifications in the preferred embodiment of the invention, herein chosen for the purpose of illustration, which do not depart from the spirit and scope of the invention.

What is claimed is:

1. A reentrant wire terminal for a glass tubular envelope comprising; an axial lead wire connected to an electrical component within the envelope and extending through a sealed end thereof, said lead wire being bent to form a sealing and first imbedded portion, a contact portion, and a second imbedded portion; said sealing and first imbedded portions being disposed at an angle not exceeding about 45 degrees from the axial lead wire, said contact portion being spaced from and outside said sealed end, and said second imbedded portion being disposed at an angle to the axial lead wire which is substantially equal to the angle of the first imbedded portion, the second imbedded portion terminating at a point spaced from said first imbedded portion.

2. A reentrant wire terminal as claimed in claim 1 wherein the contact portion is spaced away from said sealed end.

3. A reentrant wire terminal as claimed in claim 1 wherein said first and second imbedded portions are imbedded in said sealed end by clamping semi-molten glass from the envelope around both sealing portions.

3 4 4. A reentrant wire terminal as claimed in claim 1 l References Cited wherein said sealed end encloses the terminus of said UNITED STATES PATENTS second imbedded portion.

3,093,768 6/1963 Ayres 313-318 5. reentrant Wire ternnnal as claimed 1n clan-n 1 5 3,320,466 5/1967 Ayres at a]. 313*318 wherein 5 21121 axial lfeadzlvlre 1s 1Welded :10 a sine eigte nd lng 3,286,118 11/1966 vause et a1 3 31 to er sa nve o gi ig fg g P6 an Sal we JOHN W. HUCKERT, Primary Examiner. 6. A reentrant wire terminal as in claim 1 wherein said POLISSACK Assistant Examinercontact portion is disposed at substantially right angles to Us said axial lead wire. 313 43, 271, 326, 331 

